Another good point from James K. A. Smith, this time about the purpose of repetition in worship.
If you think of worship as a bottom-up, expressive endeavor, repetition will seem insincere and inauthentic. But when you see worship as an invitation to a top-down encounter in which God is refashioning your deepest habits, then repetition looks very different: it’s how God rehabituates us. In a formational paradigm, repetition isn’t insincere, because you’re not showing, you’re submitting. This is crucial because there is no formation without repetition. Virtue formation takes practice, and there is no practice that isn’t repetitive. We willingly embrace repetition as a good in all kinds of other sectors of our life—to hone our golf swing, our piano prowess, and our mathematical abilities, for example. If the sovereign Lord has created us as creatures of habit, why should we think repetition is inimical to our spiritual growth? 
 James K. A. Smith,You Are What You Love: The Spiritual Power of Habit (Grand Rapids, Michigan: Baker Publishing Group, 2016), 80, Kindle.